Help

Hi,

I can speak and understand english but sometimes, i lack words to use. I have thoughts in mind, but sometimes, I cannot speak a word (no words coming out my mouth). Most of the time, thoughts are there and when I speak, I just can't say it properly. I talk fast, so sometimes, the receiver was not able to catch up all the words i said. I tried to make slow, but it seems that all the thoughts in my mind are vanishing till I left with no words to say. When i speak in english (even when I am just reading), my tongue usually got twisted. What is the best practice for me to do?? Are there things to avoid? Please let me know. Thanks!